Idiopathic dilated cardiomyopathy (DCM) is a type of heart disease in which the organ's muscle becomes weaker. It can lead to heart failure and ventricular arrhythmia (a type of irregular heart beat) or even sudden death. The EU-funded INHERITANCE project has provided a better understanding of the genetic causes of DCM, while developing diagnostic and therapeutic strategies for patients.

“DCM affects one in 2500 adults, with an annual incidence of between 5% and 8% per 100 000,” says INHERITANCE coordinator Professor Eloisa Arbustini of the Foundation IRCCS Policlinico San Matteo. “It is one of the leading causes of heart failure due to systolic dysfunction, being responsible for 10 000 deaths per year in Europe, and it is the most common indication for cardiac transplantation in adolescents and adults.”

Early diagnosis and management of the disease is fundamental, but in spite of the fact that it is inherited in up to half of all cases, few patients are aware of the familial risk and less than 1% get genetic testing.

Familial DCM is “genetically heterogeneous”, says Arbustini. That means several different genes may cause the disease. INHERITANCE researchers have worked to characterise different types of DCM, and they undertook genetic studies to explore the molecular makeup behind the different mutations that cause the disease.

Arbustini says thousands of patients with DCM throughout Europe took part in the research project. In addition, using some of the most innovative, next-generation genetic sequencing techniques, researchers have analysed 84 genes in more than 700 of those patients.

The results have enabled successful pre-clinical and pre-symptomatic diagnosis, meaning researchers can identify family members at risk before they develop the disease.

They have also developed ground-breaking, family-tailored and optimised clinical and genetic work-up, enabling a more cost-effective use of medical resources.

“Over the course of three years,” says Arbustini, “we have obtained important new information with immediate relevance to everyday clinical practice. The greatest contribution has been our characterisation of patients with ‘laminopathies’, a subtype of DCM caused by mutations in the gene encoding for the nuclear envelope protein.”

This kind of DCM, she says, affects some 8% of all cases and carries a high risk of ventricular arrhythmias, even in the early phases of the disease.

“Another major achievement of INHERITANCE has been to provide policy makers with a healthcare model that can be applied across the continent,” she says.

Using this model to diagnose and care for families identified with genetic DCM allows doctors to provide tailored monitoring, treatment and preventive care, reduce discomfort for patients and cost compared to other treatment. Patients can receive treatment as outpatients and avoid unnecessary hospitalisation.

Arbustini says the subject of the study, familial DCM, is not only an important healthcare problem in its own right but can also serve as a model for developing improved and tailored treatments for other inherited diseases.